In current transmission housings, there are a variety of ways to drive the low and reverse gears in a planetary transmission. These current systems utilize conventional designs which yield high cost and high parasitic losses.
Many current systems include a conventional low/reverse multi-friction plate clutch pack positioned in parallel with a one-way clutch to ground a carrier of a planetary gear set to a transmission housing. These systems that utilize multi-pack clutches are inefficient and result in high parasitic losses. These prior systems also have high torque requirements, which results in relatively high cost.
Other current systems utilize a double-wrapped band in parallel with a one-way clutch to ground a carrier of a planetary gear set to a transmission housing. These systems that a utilize double-wrapped band require a relatively large amount of space to be implemented and therefore consume a large amount of space in the transmission housing. These systems that utilize double-wrapped bands require a relatively large amount of radial space to be implemented and therefore consume a large amount of space in the transmission housing. Moreover, because these prior systems with double-wrapped bands allow for slippage, which also results in inefficiency and high parasitic losses, they also have a high torque requirement, which makes them relatively expensive to manufacture and use.